| 0 |      1 | (*  Title: 	ZF/ordinal.thy
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|  |      2 |     ID:         $Id$
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|  |      3 |     Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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| 30 |      4 |     Copyright   1993  University of Cambridge
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| 0 |      5 | 
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|  |      6 | Ordinals in Zermelo-Fraenkel Set Theory 
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|  |      7 | *)
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|  |      8 | 
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| 124 |      9 | Ord = WF + "simpdata" + "equalities" +
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| 0 |     10 | consts
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| 30 |     11 |   Memrel      	:: "i=>i"
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|  |     12 |   Transset,Ord  :: "i=>o"
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|  |     13 |   "<"           :: "[i,i] => o"  (infixl 50) (*less than on ordinals*)
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|  |     14 |   "le"          :: "[i,i] => o"  (infixl 50) (*less than or equals*)
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|  |     15 | 
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|  |     16 | translations
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|  |     17 |   "x le y"      == "x < succ(y)"
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| 0 |     18 | 
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|  |     19 | rules
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|  |     20 |   Memrel_def  	"Memrel(A)   == {z: A*A . EX x y. z=<x,y> & x:y }"
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|  |     21 |   Transset_def	"Transset(i) == ALL x:i. x<=i"
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|  |     22 |   Ord_def     	"Ord(i)      == Transset(i) & (ALL x:i. Transset(x))"
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| 30 |     23 |   lt_def        "i<j         == i:j & Ord(j)"
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| 0 |     24 | 
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|  |     25 | end
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